In JP 2008-211530 A (Patent Literature 1), an optical packet buffer control device is disclosed. The optical packet buffer control device includes an optical delay line buffer including a plurality of delay lines.
An amount of delay of each fiber delay line in the optical delay line buffer is constant. Thus, an amount of delay given to an optical packet by the optical delay line buffer is a fixed discrete value. Thus, in a case where optical packets having different lengths reach the optical delay line buffer simultaneously, an excessive delay is given to the optical packets. As a result, there are some void spaces between continuously-outputted packets from the buffer. These spaces decrease link utilization.
Moreover, in order to expand an optical delay line buffer, many delay lines are required. The optical delay line buffer generally controls an amount of given delay by choosing line having enough length to accommodate the packet. Thus, in a case of expanding the optical delay line buffer, long delay lines are necessary and footprint of the buffer becomes large. In addition, signal quality is deteriorated due to long delay lines.